This invention relates to fuel cells and, in particular, to fuel cells to be arranged in stack form.
In the present day construction of fuel cell stacks, individual fuel cells are disposed one on the other and external connectors are used to hold the cells together. With this type of construction, the stack must be entirely disassembled, in order to replace a defective cell. As the number of cells grow larger, location of a specific defective cell and disassembly of the stack to replace same become extremely difficult, if not impossible. As a result, what is sometimes done is to bypass a group of cells inclusive of the defective cell and to use the stack in this form.
The above procedure, however, reduces the stack performance and requires cumbersome bypass equipment. It is, therefore, far from an entirely satisfactory solution to the problem.
Corresponding application Ser. No. 338,353, filed Jan. 11, 1982, now U.S. Pat. No. 4,397,917, assigned to the same assignee hereof describes a fuel cell stack comprised of a plurality of fuel cell packs each containing a plurality of fuel cells which are internally connected to form a unit and, therefore, are removable from the stack together and independently of the fuel cells of the other packs. Such fuel cell packs make the detection of defective cells and removal of same from the stack a simple procedure, since an entire pack may be removed from the stack and replaced without disturbing the other packs of the stack.
While fuel cell packs of the aforesaid type are thus quite advantageous, further techniques are still being explored to further enhance their usefulness.
It is an object of the present invention to provide a fuel cell sub-assembly which is adapted to facilitate removal of such sub-assembly from other sub-assemblies in a fuel cell stack.
It is also an object of the present invention to provide a fuel cell sub-assembly while is adapted to permit its removal from other sub-assemblies in a fuel cell stack without causing substantial damage to itself or the other sub-assemblies.